1. Field of the Invention
The invention generally relates to a method of forming a rotary device.
2. Description of the Related Art
Traditional rotary devices include a stator and rotor which is rotatable with respect to the stator about an axis. These rotary devices are typically formed from castings. An example of a rotary device which is formed from castings is disclosed in U.S. Pat. No. 3,780,708 to Angsten (the '708 patent). The rotary device includes a stator defining a center bore and a stator which rotates within the center bore of the stator. The '708 patent shows the stator and the rotor formed from a thick cast material. End plates are bolted into place to seal the rotor within the stator.
Additionally, with casting these components, the center bore must be honed to achieve circularity within the hole. However, this circularity can vary greatly between castings. As known to those skilled in the art of manufacturing engines, casting of engine blocks for internal combustion engines also requires machining to hone cylinder bores into the castings. Piston matching must be employed during the manufacture of the internal combustion engine. This is because the circularity of the bores and the pistons are not repeatable and vary widely. Therefore, pistons must be matched, by trial and error, to determine which ones match the bores.
The use of cast components adds a significant amount of weight to the rotary device. Additionally, because the circularity of machining the cast components varies greatly between castings, it can become very time consuming, wasteful, and expensive to employ matching between the rotor and the stator.